TY - JOUR T1 - Modular detector for a dedicated PET/CT breast scanner JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1966 LP - 1966 VL - 52 IS - supplement 1 AU - Raymond Raylman AU - Stan Majewski AU - Alexander Stolin Y1 - 2011/05/01 UR - http://jnm.snmjournals.org/content/52/supplement_1/1966.abstract N2 - 1966 Objectives Combined PET and CT breast imaging has the potential for improving the detection and biopsy of suspicious lesions the and monitoring of treatment response. To maximize the performance of the PET component of our new dual-modality scanner, several elements of our previous PEM/PET detectors were modified. Methods To adapt our first-generation PET detectors to the rapid 360deg. rotational motions inherent in CT imaging, the scintillator array, light spreader and PSPMT array that were previously dry-coupled were joined with a semi-rigid optical gel. To increase the count rate performance of the system, the original trigger configuration was changed from a single-channel scheme to a one where the triggers where distributed among four channels. The 4x3 array of PSPMTs was divided into four sectors, with the signals from each sector placed in coincidence with the four sectors of the opposing detector head. Thus, each coincidence channel processed up to one quarter the events compared to the original scheme. Coincidences were formed using a new programmable coincidence matrix unit. Finally, two FPGA-based ADC units were incorporated within the each detector unit. This arrangement reduces external cabling needs. One ADC is triggered by prompt coincidence events, the other by delayed events to estimate random coincidence rates. Results In addition to ruggedizing the detector for rapid rotational motion, the use of the optical gel improved the light-collection ability of the system to the point where signals from all of the detector elements are discernable (we were not able to uniquely identify signals from elements at the edges of the original system). The sectorized triggering scheme has improved by the count rate capability by up to a factor of four. Finally, the new ADC arrangement permitted 360deg. rotation and facilitates estimation of random coincidence events. Conclusions The ruggedized PET detectors with improved performance will facilitate high-resolution, high-efficiency, imaging for our new dedicated breast-PET/CT system. Research Support This work is supported by the NCI (R01 CA094196) ER -